1. Field of the Invention
The present invention relates to a count control apparatus. More specifically, the present invention relates to a count control apparatus that counts the number of processing operations of a processing unit such as an electronic photocopying machine or the like and which controls the processing unit responsive to the count output.
2. Description of the Prior Art
It has been a common practice in an electronic photocopying machine, for example, that a desired number of sheets being photocopied consecutively is preset and a repetitive photocopying operation is consecutively effected at a predetermined photocopying operation speed responsive to the preset number and the repetitive photocopying operation is controlled by counting the number of sheets actually photocopied and comparing the count number with the preset number. A recent model of an electronic photocopying machine is structured such that a desired number of sheets being photocopied consecutively may be preset by inputting the numerical value by the use of a keyboard of a ten key type. Such a type of numerical value entry device as allows presetting of the number of sheets in an electronic manner is more advantageous as compared with one which is of a mechanical structure such as a rotary switch or the like, particularly in case where a large number of sheets should be preset because a rotary switch must be adjustable for each of several digit positions of the numerical value.
However, it could happen that the preset number of sheets being photocopied must be changed to a new larger or smaller number, while the photocopying operation is progressing consecutively at the photocopying speed of the photocopying machine in accordance with the originally preset number of sheets. In order that a new larger or smaller number of sheets to be photocopied may be preset by the use of an electronic numerical value entry device, it was necessary in the prior art to stop the photocopying operation of the photocopying machine and then to clear the formerly preset numerical value and to reset a new numerical value for a larger or smaller number of sheets to be photocopied. In such a situation, if a new numerical value is inputted without clearing the formerly preset numerical value, a confusion is caused between the formerly preset numerical value and a newly preset numerical value. For example, assuming that the numerical value "50" has been preset and a change of the numerical value is desired from the formerly preset numerical value "50" to a new preset numerical value "35" when ten sheets have already been photocopied, entry of only the numeral "3" for the first digit causes a display of the value "03" or "3"; however, it cannot be determined whether the new preset numerical value is the numeral "3", or whether the preset numeral "3" is followed by a further entry of the numeral "5" to establish the numerical value "35", and therefore the photocopying machine must be stopped until the new numerical value "35" is fully entered, inasmuch as entry of only the numeral "3" is smaller than the number of sheets actually photocopied so far by that time. In other words, with a typical conventional electronic photocopying machine, it always happens that if a new number of sheets being photocopied is preset in the course of the consecutive photocopying operation in accordance with the previously preset number of sheets being photocopied, the photocopying machine is brought to a stop for the time period necessary for entering a new numerical value for the new number of sheets to be photocopied. The manual entry of such a new numerical value requires some time and hence decreases the efficiency of the photocopying operation, in spite of the fact that the recent electronic photocopying machines have been much improved in their photocopying speed. Thus, it is desirable that after a number of sheets being photocopied is once preset, the preset number of sheets to be photocopied may be changed as desired even in the course of the consecutive photocopying operation without interrupting the consecutive photocopying operation.